When streaming contents are to be viewed using a communication terminal curried in a movable object such as a vehicle, deterioration of images, sound dropout or the like occurs due to deterioration of communication quality (decrease or delay in the communication speed, or data loss). As a method for preventing deterioration of contents in a mobile communication terminal, there have been proposed a method of increasing a buffer size on a contents reproduction side, a method of decreasing a communication data amount by decreasing a bit rate of contents, and the like (see Patent Literatures 1 to 4 listed below, for example).
In the inventions described in Patent Literatures 1 and 2, start and end times of a communication-interrupted section and communication quality on a route are predicted based on vehicle information (road information, speed, running route and the like) to change the bit rate and the buffer, thereby preventing deterioration of the contents. In the invention described in Patent Literature 3, an optimum communication bit rate is calculated by an apparatus that mediates contents between a streaming-contents reproduction apparatus mounted on a vehicle and a contents server, and is notified to the streaming-contents reproduction apparatus, thereby improving deterioration of contents caused by deterioration of communication quality. Further, in the invention described in Patent Literature 4, by controlling the reproduction speed based on a remaining amount of the buffer at the time of reproduction of contents, discontinuity of contents reproduction caused by decrease in communication quality is improved. In the method described above, contents discontinuity associated with change of the buffer size does not occur.